1. Field of the Invention
The present invention relates to a semiconductor device. In addition, the present invention relates to an electronic device including the semiconductor device.
2. Description of the Related Art
In recent years, development of semiconductor devices including transistors has been advanced.
In the above semiconductor device, control of the threshold voltage of the transistor is important. For example, a transistor having normally-on characteristics causes various problems in that malfunction is likely to be caused when in operation and that power consumption is increased when not in operation.
As a method for controlling the threshold voltage of a transistor, a method for shifting the threshold voltage of a transistor by supplying a power source potential to a back gate of the transistor has been known (see Patent Document 1).